I’m still wondering if it was an unhappy customer (or relative of one) or a professional. A few years ago a guy who had waited 20 years shot the doctor he blamed for his mother’s death as the doctor bicycled to work at the hospital in Houston. Some folks play the long game. https://www.cnn.com/2018/08/02/us/mark-hausknecht-houston-doctor-suspect/index.html
I’m still upset when united health denied coverage for a microscope for microscopic surgery on my son